Switch operating mechanism



July 16, 1957 w. M. MocoNNr-:LL ETAL 2,799,172

' swx'n OPERATING MEcHANxsM 2 Sheets-Sheet l Original Filed Sept. 6, 1951 INVENTORS magy Joh/2 1612 Hafen. weegl M AW 5W July 16, 1957 w. M. MocoNNLL rs1-AI. 2,799,172

SWITCH' OPERATING MECHANISM original Filed sept. '6, 1951 2 sheets-sheet 2 Z v/-f/IK I i 6 l e l x E 10 l 5 7 i l1 9 I R I4 INVENTORS Wiliam. @12m/1d MC nzzel( allg; John 15?. In Holz. WQM Muhafv'wwhm/ Imm from v Unite 2,799,112 SWITCH orEnArlNG MECHANISM Original application September 6, 1951, Serial No. 245,304, now Patent No. 2,707,876, dated May 10, 1955. Divided and this application February 25, 1955, Serial No. 490,627

2 Claims. (Cl. 74-99) This application is a division of our copending application Serial No. 245,304 tiled September 6, 1951.

This invention relates to switch operating mechanisms, and in particular, to switch operating mechanisms which actuate spaced apart switches.

Many types of automatic machines including pipe testing and expanding machines and installations which mass produce close tolerance parts require switch operating mechanisms. These mechanisms must have quick, positive actions and be senstive to slight changes or variations in operation. Such switch operating mechanisms are highly desirable for machines which have high production capacities and which constitute a part of wholly automatic manufacturing facilities. They are particularly necessary in mass production operations where shutdowns are costly because of the effect upon the entire operation. Therefore, quick, positive acting switch operating mechanisms capable of effecting close and sensitive control over automatic machinery have a vital place in high production manufacturing plants.

For example, automatic pipe testing machines using test pressures ranging up to 10,000 p. s. i. must maintain iluidtight seals between the ends of the pipe and the test machine. Because there is shrinkage and expansion of the pipe length during a test cycle under these pressures, ability to maintain the seal between the ends of the pipe and the machine is dependent upon compensating irnmediately after a change in length occurs. To effectively compensate for these changes in length before breaking or damaging the seal, the machine must advance or retract that part which makes the seal with the pipe in accordance with the amount of contraction or expansion. To actuate the machine to compensate for these changes in length requires a switch operating mechanism which is instantly responsive to small changes in length and which has a quick, positive action.

Our invention provides a switch operating mechanism which has a quick, positive action and is sensitive to slight changes in machine operation thereby being highly desirable for automatic installations. Specically, our switch operating mechanism comprises a push rod having an arm extending laterally therefrom. lournaled on said arm in spaced relation is a pair of members each having two oppositely disposed projections. Spring means cooperate with one projection of each member and yieldingly holds it in a predetermined position. Adapted to engage one of two spaced switches on axial movement of the rod in either direction are means on the other projection of said members.

In the accompanying drawings we have shown a preferred embodiment of our invention in which:

Figure l is a plan view of our mechanism for actuating electrical switches with the enclosing case being shown in section;

Figure 2 is an elevation View thereof; and,

Figure 3 is a vertical section taken on the line Ill- III of Figure 2.

States Patent As shown in Figures l, 2 and 3, our switch operating mechanism comprises a push rod 1 adapted to actuate a pair of switches 2 and 3 of the plunger type. These switches are housed within casing 4 and affixed to a bracket 5. A lateral arm 6 secured to push rod 1 extends through an opening 7 in bracket 5. As shown in Figure 3, the lateral arm 6 is keyed to the push rod 1 and is in no other way journalled or otherwise supported. The lateral arm 6 has a T-head 8 welded thereto at its outer end. A rubber diaphragm 9 closes the space between the arm 6 and the bracket opening 7.

To accommodate two taper pins 10 having nuts threaded on their smaller ends, We drilled the head 8. The taper pins provide journals for a pair of bell cranks 11 and 12 each of which pivots about the pin 10 on which it is mounted in a manner more fully described hereinafter. The upper end of each bell crank has a stud 13 threaded therethrough and adapted to engage the plunger of one of the switches. A tension spring 14 connects the lower arms of the bell cranks and constantly urges stop lingers 15 against the bottom of the head 8.

Longitudinal movement of the push rod 1 in either direction moves arm 6 which in turn pivots one of the bell cranks on its taperV pin thereby operating one of the plunger type of switches. Only a slight movement of the push rod is necessary to operate one of the switches because the arrangement of the bell cranks, spring 14, and arm 6 with T-head attached thereto responds to small changes in position of the push rod. Specifically, the operation of our apparatus is as follows: A movement of the push rod 1 to the right viewing Figure 1 causes arm 6 and T-head 8 to likewise travel to the right viewing Figures l and 2. Travel of the arm 6 is in a longitudinal direction viewing Figures l and 2 and corresponds to longitudinal movement of the push rod 1 in either direction. When arm 6 is moved to the right viewing Figures 1 and 2, bell crank 12 which is likewise moved to the right pushes plunger 13 into switch 3, thereby actuating it. Right-hand travel of bell crank 12 continues until plunger 13 engages a stop (not shown) inside switch 3 whereupon bell crank 12 cocks by pivoting about pin 10. The pivot motion of crank 12 about pin 10 is in a counterclockwise direction viewing Figure 2.

During travel of the arm 6 to the right, bell crank 11 also advances in this direction. When bell crank 12 cocks and pivots about pin 10 in a counterclockwise direction, stop finger 15, a part of crank 11, engages the bottom of T-head 8 and prevents any pivotal motion of crank 11. Movement of the rod 1 to the left after a movement to the right uncocks crank 12 whereupon spring 14 returns crank 12 to the position shown in Figure 2.

Movement of the rod 1 to the left viewing Figures l and 2 causes crank 11 to operate in the same manner described above relative to crank 12 except that when crank 11 cocks, it pivots about pin 10 in a clockwise direction. During movement of the rod 1 to the left, stop inger 15, a part of crank 12, prevents bell crank 12 from pivoting about pin 10.

From the foregoing it is clear that our invention has important advantages. In the first place, it has a quick and positive action which permits close and sensitive control over automatic machines.

In the second place, our mechanism is sensitive to slight changes in operation of the machine on which it is mounted. This insures close control over the operation of a machine which is a part of an automatic assembly line. The close control over such a machine permits uniform and continuous operation of such a machine thereby affording a manufactuerer of `uninterrupted operation of automatic machinery on his assembly line.

While a certain present preferred embodiment of the y Patented'July 16, 1957`V D invention. has been herein described, it will be understood that it may be otherwise embodied within the socpe of the appended claims,

We claim:

1. Switch operating mechanism comprising a push rod, an arm extending laterally therefrom, a pair of members journaled on said arm in spaced relation, each of said members having two oppositely disposed projections, spring means cooperating with one projection of each member yieldingly holding it in a predetermined position and means on the other projections of said members adapted to engage one of two spaced switches on axial movement of said rod in either direction.

2. Switch-operating mechanism including a push rod, and arm extending laterally therefrom, a pair of opposed bell cranks journaled on said arm in spaced relation, spring means cooperating with one arm of each crank yieldingly holding it in predetermined position and means on the other ends of the bell cranks adapted to engage one of two spaced switches on axial movement of said rod in either direction.

References Cited in the tile of this patent UNITED STATES PATENTS 2,198,247 Grob Apr. 23, 1940 2,201,078 Brvington May 14, 1940 2,222,704 Brown Nov. 26, 1940 2,301,099 Upp Nov. 3, 1942 2,531,764 Binus Nov. 28, 1950 

